The implementation of Basic Rate Interface/Integrated Services Digital Network service (BRI/ISDN) is changing the way telephone loops are modeled in operation support systems, and in how services can be maintained with existing operations support systems. For example, with ISDN a subscriber to the service can initiate and effect a move of his directory or telephone number from one location to another without directly involving the operating company. The subscriber, by moving his directory number to a new location, receives his service over a new digital subscriber line. The digital subscriber line is the transport facility which carries the digital signal between the subscriber's location and the operating telephone company's network switching element.
As a result, the records of the operating company which identifies a specific transport facility to a specific telephone number cannot be readily updated to reflect subscriber moves. Thus, if the records of the operating company do not identify the transport facility which is associated with the directory number at the new location, the operating company cannot readily process trouble reports against the service.